Heart Rate Reserve
Heart rate reserve is the difference between your maximum and resting heart rate, used to calculate training zones more accurately for your fitness level.
Published by Repit Fitness · Last updated
Key facts
- Max heart rate minus resting heart rate.
- Used in the Karvonen formula for zones.
- Accounts for individual fitness via resting rate.
- Gives more personalized intensity targets.
Heart rate reserve (HRR) is the room your heart has to work — the gap between its resting rate and its maximum. Because it factors in your resting heart rate, which reflects your fitness, it produces more individualized training zones than using max heart rate alone.
It's used in the Karvonen formula, where a target heart rate is your resting rate plus a percentage of your reserve. This personalizes intensity: two people with the same max but different resting rates get different, more appropriate targets. It's a more precise way to prescribe cardio intensity.
Frequently asked questions
How do I calculate heart rate reserve?
Subtract your resting heart rate from your maximum heart rate. For target zones, add a percentage of that reserve back to your resting rate (the Karvonen method).
Why use heart rate reserve instead of max heart rate?
Because it includes your resting heart rate, HRR accounts for your individual fitness, producing more personalized and accurate training zones.
This article is general information, not medical advice. Talk to a doctor or registered dietitian before making changes if you have a health condition, are pregnant or take medication.
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